Rectifier cooling system control



March 14, 1933. wlNOGRAD 1,901,071

RECTIFIER COOLING SYSTEM CONTROL Filed Oct. 22, 1930 lnvemar Ham may IPatented Mar. 14, 1933 rattan UNITED STATES PATENT OFFICE nnnonnWINOGRAD, or GOLLINGSWOOD, NEW anBsEmnssIe-non, :BY ivinsnn ASSIGN-MENTS, TO ALLIs-onALivinns MANUFACTURING COMPANY, or MILWAUKE WIS-CONSIN, A GORZPORATION OF DELAWARE RECTIFIER COOLING SYSTEM CONTROLApplication filed October 22, 1930. Serial No. 490,462.

- This invention relates to improvements in electric current rectifyingsystems employing a rectifier of the metallic arc type and particularlyto means for incorporation in such system by which the coolingof therectifier is controlled.

Electric current rectifiers of the metal enclosed type are usually madedouble-walled to provide a path for the circulation of a cooling mediumthrough the space between the walls. The supply of cooling medium isgenerally controlled in such way that the supply is shut-0H when therectifier is put out of operation for any'reason suchas when either thealternating current supply or the direct current output are cut off orwhen back-fires oc cur. Such action is not desired because thetemperature of the rectifier tank continues to rise for some time due tothe condensation of the mercury vapor within the tank after therectifying action ceases. Such increase in temperature operates theusual protective devices applied to the installation unnecessarily.Complete condensation of the mercury vapor requires a long time, due tothe heat of vaporization released, in the absence of a supply of coolingmedium and the vacuum within the rectifier may drop too low to permitimmediate restarting. The supply of cooling medium should therefore becontinued until all the mercury is condensed and the heat released hasbeen removed. In addition to the above, unless the supply of coolingmedium to the walls of the tank is continued after operation ceases.mercury may condense on the anodes which are constructed with a separatecooling system, and may cause backfires in the rectifier. It istherefore desirable that the supply of cooling medium be continuedautomatically after the rectifier has been shut down until it hasreached a temperature at which the supply of coo ing water may be safelyinterrupted without incurring the danger of future disturbances instarting or in operation.

It is, therefore, among the objects of the present invention to providea control system for the cooling medium supply of an electric currentrectifier which will maintain the supply of cooling medium until therectifier has reached a pre-determined temperature.

Another object of the invention is'to provide a control'system for thecooling medium supply of an electric current rectifier which willmaintain the supply of cooling medium until the rectifier has reached apro-determined temperature regardless of the fact that the rectifier isno longer in operation.

Another object of the inventionis to provide a control system for thecooling medium supply of an electric current rectifier which willautomatically maintain a supply of cooling medium until the rectifieriscooled toa pro-determined temperature and will automatically startsupplying cooling medium to the rectifier as soon as the rectifier isput into operation. i 1

Objects and advantages, other than those above set forth, will beapparent from the fol- 1 lowingdescription when read in connection withthe accompanying drawing which diagrammatically illustrates oneembodiment of the present invention.

Referring more particularly to the drawing by characters of reference,the reference numeral 1 designates an alternating current supply linewhich is connected through a circuit breaker 2 with the primary winding3 of a transformer, the secondary winding & of

which is connected with and supplies current to the anodes (not shown)of arectifier 6. The rectifier is made double-walled as indicated by thedotted lines to provide a path for the circulation of a cooling mediumwhich is supplied from a suitable source through a pipe 7. The coolingmedium circulates through the space between the walls of the rectifieras shown by the arrows and discharges therefrom through a pipe 8.

An electro-magneticallyv operated valve 9 is arranged in supply pipe 7and is arranged to be operated by connection with a source of controlcurrent 11 as will be seen hereinafter. When circuit breaker 2 is open,as shown, a pair of auxiliary contacts 12 connected with the coil of thevalve 9 is also open. Asecond pair of contacts 13, also connected in thecircuit of the valve coil, are controlled by the expansion andcontraction ofathermostatic the cooling medium discharging from therectifier.

The valve 9 is keptopen by-the energization of the coil thereof whencircuit breaker 2 is closed to connect supply line 1 to transelement 14arranged in the outlet pipe 8 for formers 3 and 4: and to bridgecontacts 12 regardless of the position of thermostatic element 14 and isalso kept openby bridging of contacts 13 when thermostat 14 is expandedregardless of the open position of circuit breaker 2. Thus when therectifier is cold,

element'may be located wherever desired in was the path of the coolingmedium and also that any well-known type of thermostatic element may beused. It will also be understood that the auxiliary contacts 12 may beso arranged as to be-bridged by another portion of the switchingequipment in the installation such as the usual direct current outputline circuit breaker or any'of the relays used to obtain automaticoperationof the rectifier as is well known.

Although butone embodiment of the present invention has been illustratedand described, it will be apparent to those skilled in'the art thatvarious changes and modifications may be made therein without de 7parting from the spirit of the invention or from the scope of theappended claims.

The invention claimed is:

1'. In an electric current rectifying an electric current rectifier apath'for the circulation of a cooling me- 'diurn, a source'of electriccurrent supply for said rectifier, means for connecting said currentwith the rectifier, thermostatic means arranged in conjunction with saidrectifier, and a valve arranged in the path of and controlling the flowof the cooling medium, said connecting means and" said thermostaticmeans cooperating to control the operation of said valve. 1

2. In an electric current rectifying system, an electric currentrectifier formed to provide' a path for the circulation ofa coolingmedium, a source of electric current supply for said rectifier, meansfor connecting said current'with the said rectifier, thermostaticsystem, formed to provide means arrangedadjacent the path or the coolingmedium, a source of control current, and electro-magnetically operatedvalve arranged in the patlrof and controlling the flow of the coolingmedium, said connecting means and said thermostatic means cooperating toconmeans arranged adjacent the path of the cooling medium, a source ofcontrol current, and an electro-magnetically operated valve arrangedm'the path of and controlling the flow; of thegcooling medium, saidcircuit breaker connectin an o cratin coil of said valve with saidsource of control currentup- :on said operating connection of saidcircuit breaker to open said valve, Sa-1Clfl1BI11'lQ' static meansconnecting the coil'of'said'valve for opening the same withsaid sourceof control current at a; predeterminedtemperatu e of the cooling medium.

4-. In an electric current rectifying system, alternating currentsupplyline, an electric current rectifier having doublewalls to providefor the circulation of a cooling medium therebetween, a circuit breakeroperative to connect said supply'line with said rectifier, thermostaticmeans arranged in he path of the cooling medium, a source of 4, Lcontrol. current, and an electro-magnetically cpcrated valve arranged'inthe pathof and I controlling the flow of the cooling medium, saidcircuit breaker connecting an operating coil for said valve with saidsourceof control current upon operation of said circuit breaker toconnect said supply line with said rectifier, said thermostatic meanscon- 'necting said coil of said valve to said source of control. currentat a predetermined temperature 'of the cooling medium, said circuitbreaker and said thermostatic means operating independently of eachother. In combination, an electric current rectifier comprising meansefiective to permit the circulation of a cooling medium thereabout,source of electric current supply for the said rectifieiymeans operativeto effect connection of said source with the said rectifierto causeoperation thereof, means operative responsive to the connection of saidsource with the said rectifier and effective upon such operation tocontrol the said circulation of the cooling medium, and means operativedependence upon the temperature of the cooling medium and efi'ectiveupon such operation to control the said means for controlling thesaid'circulation of the cooling Imedium. Y i v 6. In combination, anelectric current rec-- tifier cemprising means disposed to permit thecirculation of a cooling fluid thereabout, a source of electric currentsupply for the saic rectifier, a switch disposed to be operated toconnect the said source of current with the said rectifier to causeoperation thereof, electro-magnetically actuated means operative uponoperation of the said switch to connect the said source with the saidrectifier to permit the said circulation. of cooling fluid about thesaid rectifier, and thermostatically actuated means operative independence upon the temperature of the cooling medium at and above apre-determined temperature, the last said means being operative uponsaid actuation thereof to cause operation of said electro-magneticallyactu ated means to permit said circulation of the cooling fluid aboutthe said rectifier.

7. In combination, an electric current rectifier having a chamberthereabout to permit the circulation of a cooling fluid therethrough, asource of electric current supply for said rectifier, a switch disposedto be operated to connect the said sourceof current with said rectifierto cause operation of the latter, an electro-magnetically actuated valveoperative to control the said circulation of cooling fluid through thesaid chamber, means associated with and operated upon actuation of saidswitch to connect said source with the said rectifier to cause actuationof the said valve to permit flow of said fluid through said chamber, andthermostatically actuatedmeans operative in dependence upon thetemperature of the cooling fluid flowing from the said chamber andefiective at and above a pre-determined temperature of such said fluidto cause actuation of said valve to permit flow of cooling fluid throughsaid chamber, the said thermostatically means being operative to causeoperation of the said valve independently of the operation thereof bysaid means associated with said switch. 7 1

In witness whereof I hereto afiix my signature this 21st day of October,A. D. 1930.

HAROLD WINOGRAD.

